Improvement in the processes of amalgamating ores



l. F. SANDERS.'

Processes'Uf'AmaIga'mvatiyng Dres.

No`.150,793. Y Y PatentedMaymjIaM.

UNITED STATES PATENT Prion.,

JOHANN F. SANDERS, OF LOUISVILLE, KENTUCKY.

IMPROVEMENT INV THE PROCESSES OF AMALGAMATING ORES.

Specification forming part of Letters Patent No. 150,793, dated May 12, 1874; application filed April 20, 1874.

To all whom it may. concern:

Be it known thatI, JOHANN FRIEDRICH SANDERS, of Louisville, in the county of Jefferson and State of Kentucky, have invented a new and Improved Process of Treating and Amalgamating Auriferous Orcs, oi' which the following is a specification:

In the accompanying drawing, Figure l represents a vertical longitudinal section of the apparatus I prefer to use for carrying my invention into effect.' Fig. 2 is a plan or top view of the same.

The apparatus herein illustrated forms the subject-matter of a separate application of a patent, which is filed at the same time with the present.

Similar letters of reference indicate corresponding parts in both figures.

This invention has for its object to reduce as much as practicable the expense of separating gold from the 'ores or inferior metals containing the same; and consists more particularly in exposing' suclrores or metals to a blast of hydro-oxygen gas, thereby reducing or oxidizing the ores, vaporizing the gold, and thus by vaporization bringing the gold into condition focondensation and convenient separation, the vaporsbeing carried over a sheet of water, which lies on a bed of quicksilver, so that the water will condense the vapors and carry the products of condensation in'contact with the Quicksilver, which will properly amalgamatc the gold. The invention also consists in a new chemical means of treating the molten ore in the furnace, for separating in the furnace the molten gold from the molten quartz or silicium which will not vaporize, all as hereinafter `more fully de` scribed.

By practical experiments I have ascertained that a blast of hydro-oxygen gas will give the greatest amount of heat for the purpose of reducing or oxidizing the ores, and that such blast has the greatest chemical effect, next to the light ofthe sun, on said ores. A blast of the kind named can be`used at will either as a reducing-blast by melting the ore and absorbing in the form of vapor the metallic constituents of the ore from the non-vaporing .quartz or silicium and other non-Vaporizing constituents; or, it can be used as an oxidizing-blast for oxiding all the baser metals and separating therefrom in the form of vapor the gold that was mixed with such baser metals. In the first casethat is to say, for a reducingblast, it is necessary to use about two volumes of hydrogen gas to one volume of oxygen gas; while in the second case-that is to say, for an oxidizing-blast, a surplus of oxygen gas is necessary, or oxygen gas alone may be used. These gases are obtained by suitable processes well known in the arts and sciences, and I do not consider it necessary to give the formula for making the same.

The gases are, through a proper tuyere, A, conducted into the interior of the furnace B, which interior contains the ore to be reduced. rIlhe gases 4on being ignited melt the contents of the furnace and carry away with them through the passage A the vaporized products of combustion, in whichinvariably the larger proportion of the gold contained in the ores will he carried oif. These vapors are conducted through a passage, a, into a trough or vessel, O, which contains at its bottom a bed, D, of quicksilver, upon which a sheet, E, of water is placed. Gold water is, through a pipe', b, continuously sprinkled or conducted into this vessel C, the surplus water escaping through openin gs el at one end.. The cold-water spray coming from above, as indicated, passes through the vapors that are escaping from the furnace, and serves to force such vapors more or less into contact with the cold water, to cool and condense the same and separate from them the condensed particles of gold which fall -upon the surface of the water in the form of tine spray. For further insuring the proper absorption of the gold contained in the vapors, a transverse plate, e, is Y formed in the vessel O, whereby the vapors are carried very close to the surface of the water. Finally, the vapors that have been deprived of all the gold contained in them are carried oft' through a pipe or chimney, f. The gold that enters the water E passes through the same by its gravity into contact with the lquicksilver D, and is absorbed by the quicksilver, owing to the chemical aflinity of this metal for gold, while the other metals that may have been condensed from the vapor, and all othersolid substances thatmay have reached the quiclrsilver, will remain between the quicksilver and water without combining with the Quicksilver. It is then only necessary to draw olf the quicksilver after the process has been continued for a certain length of time, and to separate from it, by the welldrnown processes now usually followed, the gold that was absorbed by it. In order to prevent all the non-auriferous products of condensation which pass through the water and do not fall through the quichsilver from forming a lilm between the quiclrslver and water, and preventing the gold from reaching the quicksilver, a proper stirring apparatus may be employed within the vessel C, so that the contact of the water with the quicksilver may never be entirely interrupted. Gases that escape through the pipe or chimney f may, if they are supposed to contain valuable ingredients, such as sulphur; Src., be conducted into suitable apparatus for further utilization. The furnace B should be properly heated by the blast before the ore is put into it, an opening, h, being formed in the top of the furnace for admitting the ores,said openingbeingsubsequentlyclosed by a proper plug. It must be Observed that the quartz or silicium that is contained in the ore cannot be changed into vapor by this blast, but it fuses readily under the influence of the blast, and by fusing sometimes carries small particles of gold along with it; and'in order ,to separate this gold from the fused quartz or silicium I add about two to six parts of oxide of lead (litharge) or galena (sulphate of lead) to one part of the gold which is supposed to be in the charge. This oxide or sulphate of lead, when molten, becomes lead, which has in -the molten state the same degree of aflinity for molten gold which quicksilver in the cold (state has for cold gold. I employ the oxide nace, and the smelting-process continued as before. The process of sublimation and con centration is then renewed until the furnace is nearly lilled with concentrated metals-th at is to say, with the lead containing the gold. A surplusage of oxygen gas is then used in the blast, for oxidizing the lead and all other base metals that maybe in the mass contained within the furnace, and the precious metal will then be vaporized4 and separated from the lead, and carried away into the vessel C, there to be condensed, in the same manner" already described. This process of oxidation goes on very rapidly, and care must be taken that the temperature in the furnace is not too high during oxidation.y In fact it should notbe higher than to bring the mass to a quiet boiling-point, and to prevent it from spattering spontaneously. Vhen the lead is all oxidized it hard ens, and becomes a litharge-powder, and a molten mass of nearly pure gold, having a brilliant metal shine and a slightly greenish color, remains in the furnace, and can be poured off or vaporized, as before. The reducing process, at first described, is now resumed. Admixtures of all other metals that maybe contained in the ores enter partly in combination with the silicium when the same is in a liquid state, and are, when the oxidizing-blast is admitted into it, oxidized, and do not, therefore, enter into amalgamation with the quicksilver. Therefore, the gold will be very rapidly and cheaply separated from all the metals and other minerals contained iu the ores, and the desired effect obtained. I may state that in carrying this process into etlect a series of furnaces, of substantially the construction shown, may be used, and the residuum in onefurnace may be partly or en tirely resubmitted to action in =another furnace, and so on, until the entire separation of' the gold shall have been Veffected--as far, at least, as such separation is at all practicable;

l. The process of separating gold from the ores by vaporizing it, and conducting the vapors over a sheet of water that rests on a bed of quicksilver, substantially as and for the purpose described.

2. rlhe process herein described of separating, by the oxidizing-blast, the gold from the oxide of lead which wasused to separate it from the molten quartz or silicium, as described, and of subsequently recovering the gold from the vapors by condensation, in the manner described.

lVitnesses: J. F. SANDERS.-

A. V. BRIEsEN, E. C. WEBB. 

